The field of the invention generally relates to tumbler clothes dryers, and more particularly relates to clothes dryer bulkheads and a method of manufacturing such bulkheads.
As is well known in the art, tumbler clothes dryers typically have a horizontally disposed tumbler cylinder or drum that is rotated by a belt drive to tumble the clothes inside the drum. In the normal arrangement, the ends of the drum are covered by stationary panels commonly referred to as bulkheads which serve a number of functions. First, the bulkheads serve to retain the clothes within the drum. Second, the bulkheads provide a substantially air tight seal so that hot air can be drawn through the drum. Third, the drum is supported by bearings which are mounted to the bulkheads.
Prior art bulkheads are typically constructed by stamping a metal blank to form a disc or panel that has a raised cylindrical plug portion which is sized to be surrounded by a sealing gasket and then inserted into an end of the drum. Mounting brackets are mounted to peripheral side portions of the disc by a fastening technique such as welding, and a pair of suitable drum support bearings such as rollers or glide pads are attached to lower peripheral regions of the disc. In fabrication, the rear bulkhead is attached to the back panel of the dryer cabinet by inserting screws through the mounting brackets which have stand-off legs to provide a heater box space between the bulkhead and the cabinet back panel. After the drum is properly supported on the rollers and positioned around the gasket of the rear bulkhead plug portion, the plug portion of the front bulkhead is inserted into the front end of the drum, and then the mounting brackets of the front bulkhead are screwed to the front edges of the side panels of the dryer cabinet.
In one typical prior art arrangement, the pair of drums support bearings (e.g. rollers or glide members) are mounted to the disc at respective locations approximately 45.degree. and 30.degree. up from the bottom with the higher mounting location being in the direction of rotation of the drum. The mounting brackets, which are relatively small and have relatively small vertical span to reduce complexity, size, and cost, are attached to respective mid-level portions of the disc at approximately 90.degree. up from bottom with screws that are only slightly above and below the 90.degree. positions.
There are serious drawbacks with the above described bulkhead assembly and method of manufacture. First, with the mounting brackets being welded to the disc or panel, there is the cost of labor involved in the welding process, as well as the cost for additional parts. Further, the welding process increases the dimensional tolerances of the bulkhead assembly thereby sometimes making it difficult to mount the bulkhead to the cabinet panel. For example, the bulkhead or the cabinet panel may have to be flexed or bowed to align the corresponding screw holes, and this dimensional instability detracts from the rigidity of the dryer. Also, because the mounting brackets are made relatively small to minimize cost, the assembly is relatively weak and is susceptible to bending, flexing, or vibrating. Further, there are relatively large moment arms between the rollers or glide pads that support the drum and the mounting locations of the mounting brackets. Thus, the disc may have a tendency to deflect or vibrate.